1. Field of the Invention
The present invention relates to an excavator for excavating a ditch under the ground and a method for excavating a ditch.
2. Description of the Related Art
There are works for excavating a ditch under the ground in basic civil engineering work. And, there was a problem regarding a flatness of ditch wall of ditch as excavating the ditch.
An example to object an improvement of the flatness is disclosed in Japanese Patent Application Laid-Open No. hei 11-93202. Hereinafter, the conventional excavator is explained by the case of excavating the underground ditch vertical to the ground, referring to FIG. 5 showing a front view of the excavator, FIG. 6a showing a status connecting a underground clinometer to a connection rod, FIG. 6b showing a cross-sectional plan view of a cutter post included in a ditch excavating body, FIG. 7 showing a block diagram of the clinometers and data processing means respectively, and FIG. 8 showing an example of a display screen.
An excavator 1 comprises an excavating device main body 2 consisting of a traveling body 2a and a revolving body 2b disposed on the traveling body 2a. The revolving body 2b is equipped with a gate-shaped frame 3. The frame 3 is supported with a leader 4 being slide in the approximately horizontal direction by a slide cylinder 4a. The leader 4 is installed to a rotation-driving device 7 ascended and descended by an oil pressure cylinder, and the driving device 7 is installed to a driving sprocket 6b driving in clockwise and counterclockwise.
A housing bottom end of said device 7 is connected with a cutter post 6a having a plurality of elements, and in the bottom end, a driven sprocket 6c is installed. Also, an excavating body 6 is formed with an endless-typed excavating chain 6d installed between said driving and driven sprockets. The excavating chain 6d equipped with an excavating blade or an excavating edge 6e is driven together with the driving and the driven sprockets, then, the excavating body 6 is moved to the transverse direction in the underground to excavate a ditch 100.
Underground clinometers 11-14 are disposed on said cutter post 6a, a ground clinometer 15 is disposed on the traveling body 2a. The underground clinometers, as shown in FIG. 6a, consist a clinometers assembly connecting up and down through a connecting rod 16, a length scale of each connecting rod 16 becomes a spaced scale between the underground clinometers. An electric wire 17 connecting them electrically is wired along said connecting rod 16.
On the other hand, as shown in FIG. 6b, the cutter post 6a is formed with not only a supply hole 18 of air, etc., extended to the up and down directions (the depth direction in FIG. 6b), but also a clinometer insert hole 19, parallel to the supply hole, and in the inset hole 19, the clinometers assembly is inserted, as shown in FIG. 6a. 
A data processing means 40 as shown in FIG. 7 is disposed on an operating chamber 2c of said revolving body 2b. The data processing means 40 consists of a data logger 41 and a personal computer 42 (hereinafter referred to as PC). Said data logger 41 is connected with the underground and the ground clinometers 11-15 through the electric wire 17, and inputs an output analogue signal of the clinometers respectively. Said PC 42 calculates an inclination or a bent status of the cutter post 6a from a data recorded in the data logger 41 to display it on a monitor screen every moment.
A display screen of said PC 42 is explained referring to FIG. 8. The display screen is displayed with a depth factor numerical value 51, a bent curve 52 of the cutter post 6a, inclination angles 53A, 53B of inner surface direction and outer surface direction in predetermined depth, and bent amounts 54A, 54B and so on of the cutter post 6a to the inner surface direction and outer surface direction. With this, the current inclination status or bent status of the cutter post 6a can be known.
However, said conventional excavator can measure an inclination or a displacement of ditch wall only in a hole unit rather than the whole ditch wall. And it does not have a function to process an inclination data of the whole ditch wall in real time.
In order to excavate a ditch having high precision ditch wall with more excellent verticality under the ground, it is necessary to obtain not only the inclination of ditch wall in the present position of excavating body but also the whole shape of the ditch wall (history of inclination). However, in the conventional excavator, it is difficult to excavate the ditch with the ditch wall of high precision because it cannot comprehend the whole shape of ditch wall.
It is therefore an object of the present invention to provide an excavator for a ditch and an excavating method capable of excavating the ditch having the ditch wall of high precision with more excellent flatness by comprehending the whole shape of the ditch wall.
The excavator of the invention comprises as follows:
an excavating body having an excavating element and a clinometer for detecting an inclination angle of ditch wall of excavated ditch;
a traveling distance recorder for measuring a moving distance of the excavator;
a calculator for calculating and accumulating an inclination signal of every moving distance of said excavator on the basis of the inclination signal outputted from said clinometer and a moving distance signal outputted from said traveling distance recorder; and
a display device for displaying said inclination signal accumulated outputted from said calculator.
In this case, an operator can operate the excavator recognizing the whole shape of ditch wall shape changed every moment by a monitor because accumulated inclination signal, for example, is displayed as a ditch wall shape on the monitor. Accordingly, it is possible to excavate the ditch with high precision flatness of the ditch wall.